Dept. of Merchandising: The Touch That Turns Sapphires to Gold

That didn’t take long. It’s been one day since Prince William announced his engagement (and it is his engagement; as he said at a press conference, “I’m very glad that I have done it”) to Kate Middleton, and already the souvenirs abound. There are mugs and T-shirts, just like for First Weddings here at home, but that is stuff for Middleton’s old crowd—that is to say, commoners. For a more regal form of kitsch, the Royal Crown Derby has commemorative china swans named William and Catherine, which retail for approximately nine hundred and fifty dollars. Assuming the role of overeager grandparent, the company has also planned “a series of cygnets” to “mark the arrival of any little princes or princesses.”

Another item: the Kate Middleton thimbles, available on eBay for about $17.50 for a lot of five. Perfect for creating an all-Middleton finger-dance troupe.

The royal engagement has also boosted business for Daniella Issa Helayel, who designed the dress that Middleton wore to the announcement. The cameo has triggered a blip in demand (the dress is totally sold out in London) that would likely be dwarfed by the coming surge if Issa is, as rumored, chosen to design Middleton’s wedding gown.

Another business benefiting from Middleton’s news is her parents’ party-paraphernalia company, Party Pieces. The number of visitors to the company’s Web site shot up immediately, according to Alexa, a company that offers traffic data. It’s tough to picture Party Pieces’ wedding offerings—“paper party boats,” “wedding cake party bubbles,” a “giant dress up cracker”—going over well with the royal family, but Middleton, who has said she will continue working for the company until closer to the big day, may want to raid the warehouse to get an early feel for being a princess.

Andrew Morton, the author of “Diana: Her True Story,” may win the Cashing In prize with his book on the royal couple, on which he is, according to a spokesperson for his publisher, “already at work.” It will be biography and memorabilia in one, set to come out within days of the wedding.